1. Field of the Invention
The present invention relates to a headphone, and, more particularly, to a headphone having left and right housings, which accommodate drive units, mounted at respective ends of a headband through hangers.
2. Description of the Related Art
To, for example, enjoy music while preventing sound from leaking to the outside, a headphone has hitherto been widely used. In general, a headphone has a structure in which left and right housings are mounted to respective ends of a headband through hangers. In the housings, drive units including small speakers are disposed. Therefore, by passing electric current through voice coils of the drive units, sound is reproduced by the drive units.
Accordingly, to supply sound signals to the respective drive units in the left and right housings, a cord is connected to the drive units in the left and right housings. Here, the following two methods are available as methods of drawing out a cord of a headphone. In the first method, cords are separately drawn out from the left and right housings. In the second method, a cord at the right housing is passed through the headband and is led into the left housing, and a cord that supplies driving current to the left and right drive units is aligned to draw out the resulting cord from the left housing. A user may feel that the first method is troublesome and causes discomfort because two cords, that is, the left and right cords, are drawn out to a neck. In contrast, in the second method, one combined cord is drawn out from the left housing, so that the user can feel that the second method is less troublesome.
However, the second method, in which the cord that is connected to the drive unit in the right housing is passed through the headband and is connected to the left housing, uses a mechanism for performing stretching/compressing adjustments on the cord in accordance with an adjusting operation of a stretching/compressing mechanism for adjusting the distance between each housing and the headband. As such a stretching/compression mechanism, for example, a structure in which the cord is bent and accommodated in an intermediate slider case or the like is proposed, in addition to a structure using a method in which the cord is exposed directly to the outside. FIG. 1 shows the structure in which the cord is exposed to the outside. Here, a housing 1, which accommodates a drive unit, is rotatably mounted to a hanger 2. In addition, a slider 3, mounted to the hanger 2, is slidably connected to a slide hole of a slidably supporting portion 5 attached to ends of headbands 4.
Slidably adjusting the slider 3 with respect to the slidably supporting portion 5 makes it possible to adjust the distance between each headband 4 and the housing 1. In this case, an excessive portion of a cord 6 is exposed so as to project sideways. That is, the stretching/compressing structure is achieved as a result of changing the amount of projection of the cord 6 that is bent and projected.
In the stretching/compressing structure of the cord 6 shown in FIG. 1, as is clear from FIG. 1, the cord 6 is exposed sideways, and the cord 6 moves freely at this portion. Therefore, for example, the cord 6 may break due to external shock, or may be caught by a different member.
FIGS. 2A and 2B show a headphone in which an excessive portion of a cord 6 is bent and accommodated in a slider case 8. That is, a slider 3 is connected to the lower end of a headband 4, and is slidable with respect to the slider case 8 connected to the upper end of a hanger 2.
Therefore, as shown in FIG. 2A, when an adjustment is made so that a housing 1 approaches the headband 4, the excessive portion of the cord 6 is held in a bent state in the slider case 8. In contrast, as shown in FIG. 2B, when the housing 1 is moved away downward from the headband 4, the slider 3 is moved out upward from the slider case 8, so that the cord 6, connected to the slider 3, is also drawn out from the slider case 8.
In the structure shown in FIGS. 2A and 2B in which the cord 6 is bent and held in the slider case 8, when the slider case 8 that causes the cord 6 to be formed in a U shape is too small, the cord 6 is too short when the slider 3 is drawn out by a large amount. Therefore, the cord 6 breaks. Consequently, the slider case 8 that bends and holds the cord 6 needs to be made long to a certain extent in a vertical direction. As a result, the relatively large slider case 8 needs to be provided, thereby preventing the headphone from becoming compact.
Further, for example, Japanese Patent No. 3520531 discusses the following headphone. In the headphone, a cord is disposed in a holding groove of a headband so as not to be capable of being stretched and compressed. In addition, a housing is mounted to the headband so as not be adjustable. Further, a head cushion is mounted to the lower side of the headband so that an actual height is adjusted by the head cushion.
In this structure, even when the head cushion is maximally stretched, the head cushion must not interfere with the headband. Therefore, the headband becomes large, resulting in the problem that a portion that is mounted to a head becomes disproportionately large. In addition, since the portion that is mounted to the head includes two components, the headband and a suspender constituting the head cushion, the number of components is increased, thereby increasing weight.